• Journal of Korea Water Resources Association
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• v.32 no.6
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• pp.657-664
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• 1999

This paper introduced the basic theory of LRCS(Linear Reservoir and Channel System) rainfall runoff model proposed by Korean researchers(Lee and Lee, 1995), and discussed the change of model output according to objective functions in sensitivity analysis and calibration process of model. It proposed "hat" matrix and affluence measures for affluence analysis of parameters in calibration, and investigated relationship between change of model output according to error propagation in parameter estimation, and sensitivity of model output according to variance of model output and change of parameters. Accuracy of parameter estimates was known by analysis of sensitivity coefficient, diagonal element $h_i$ and $D_i$._i$.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1358-1363
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• 2004

The objective of this work is to propose calibration facility in which a thin film type heat flux sensor can be calibrated under convective flow condition by using a small wind tunnel with the constant temperature plate condition. A small wind tunnel has been built to produce a boundary layer shear flow above a constant temperature copper plate. 12-independent copper blocks, thin film heaters, insulators and temperature controllers were used to keep the temperature of flat plate constant at a specified temperature. Three commercial thin film-type heat flux sensors were tested. Convective calibrations of these gages were performed over the available heat flux range of $1.4{\sim}2.5kW/m^2$. The uncertainty in the heat flux measurements in the convective-type heat flux calibration facility was ${\pm}2.07%$. Non-dimensional sensitivity is proposed to compare the sensitivity calibrated by manufacturer and that of experiment conducted in this study.

• Journal of Korea Water Resources Association
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• v.39 no.8 s.169
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• pp.677-690
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• 2006

The LH-OAT (Latin Hypercube One factor At a Time) method for sensitivity analysis and SCE-UA (Shuffled Complex Evolution at University of Arizona) optimization method were applied for the automatic calibration of SWAT model in Bocheong-cheon watershed. The LH-OAT method which combines the advantages of global and local sensitivity analysis effectively identified the sensitivity ranking for the parameters of SWAT model over feasible parameter space. Use of this information allows us to select the calibrated parameters for the automatic calibration process. The performance of the automatic calibration of SWAT model using SCE-UA method depends on the length of calibration period, the number of calibrated parameters, and the selection of statistical error criteria. The performance of SWAT model in terms of RMSE (Root Mean Square Error), NSEF (Nash-Sutcliffe Model Efficiency), RMAE (Relative Mean Absolute Error), and NMSE (Normalized Mean Square Error) becomes better as the calibration period and the number of parameters defined in the automatic calibration process increase. However, NAE (Normalized Average Error) and SDR (Standard Deviation Ratio) were not improved although the calibration period and the number of calibrated parameters are increased. The result suggests that there are complex interactions among the calibration data, the calibrated parameters, and the model error criteria and a need for further study to understand these complex interactions at various representative watersheds.

• Journal of the Korean Society for Nondestructive Testing
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• v.19 no.4
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• pp.294-299
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• 1999

In this paper, the calibration system for contact transducer has been developed to improve the reliability of the inspection result of ultrasonic testing on rotors. This system consists of signal processing parts: (oscilloscope, spectrum analyzer, pulser/receiver), standard block, and user interface program. Signal processing for the calibration system was performed quickly with high accuracy. The developed system has been applied to a practical calibration of probe using the non-destructive testing on rotors, and demonstrated high sensitivity and precision.

• JSTS:Journal of Semiconductor Technology and Science
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• v.17 no.4
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• pp.543-551
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• 2017

SOL (Short, Open and Load) calibration based on iterative error sensitivity is proposed in this paper. With advanced SOL calibration, unknown parasitic parameters at on-chip terminations are accurately estimated up to 20 GHz. Artificial terminations are designed on printed circuit board (PCB) to experiment the proposed method. On-chip SHORT, OPEN and LOAD fabricated inside silicon shows the accuracy of proposed calibration method through the comparison with known fixture S-parameter after de-embedding.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.4C
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• pp.400-406
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• 2006

Knowledge of camera parameters, such as position, orientation and focal length, is essential to 3D information recovery or virtual object insertion. This paper analyzes the error sensitivity of focal length due to position error of feature points which are employed for self-calibration. We verify the dependency of the focal length on the distance from the principal point to feature points with simulations, and propose a criterion for feature selection to reduce the error sensitivity.

• Analytical Science and Technology
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• v.23 no.1
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• pp.24-35
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• 2010

To learn more about the calibration properties of reduced sulfur compounds (RSCs) by the combination of gas chromatography(GC)-pulsed flame photometric detector (PFPD) and thermal desorption method, a series of calibration experiments were conducted on the basis of both internal and external calibration approaches. For these experiments, gaseous standards of 4 RSCs ($H_2S$, $CH_3SH$, DMS, and DMDS) were prepared at two different concentration levels of both low (10, 20, 50,and 100 ppb) and high ranges (100, 200, 500, and 1000 ppb) along with $CS_2$ as an internal standard. First, the external calibration results were compared between fixed standard volume (FSV) and fixed standard concentration (FSC) method. Secondly, FSV-based calibration results were compared between external and internal calibration results. As FSV method suffers from sensitivity variations less significantly than FSC, the former is recommended to maintain the consistency in GC-TD sensitivity for RSC analysis. In addition, when the calibration data were examined in terms of RSE between external and internal calibration data, the results were not consistent enough to show improvements in internal method. Hence, diverse efforts are desirable to optimize the reproducibility in terms of GC-TD sensitivity for RSC analysis.

• Journal of Korea Water Resources Association
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• v.32 no.6
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• pp.665-674
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• 1999

This paper confirmed the applicability of model to Korean rivers through the calibration and sensitivity analysis of LRCS rainfall runoff model for 18 storm events of Songriweon station in Nakdong river system, and achieved that LS and WLS were better than LAD by model fitting results. Diagonal element of "hat" matrix and affluence measures were used by analysis of parameter estimates, and parameter IL was the most important parameter in model output. By the results of error propagation according to parameter error, parameters IL, TP, F1 were affected by error propagation, and this is measure of sensitivity for the model output. This paper confirmed the relationship of calibration and sensitivity analysis of model through analysis of sensitivity coefficient, diagonal element $h_i$ and $D_i$._i$.

• Journal of Radiation Industry
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• v.17 no.4
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• pp.471-479
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• 2023

In In-situ radioactivity measurement techniques, efficiency calibration models use predefined models to simulate a sample's geometry and radioactivity distribution. However, simplified efficiency calibration models lead to uncertainties in the efficiency curves, which in turn affect the radioactivity concentration results. This study aims to develop an efficiency calibration optimization methodology to improve the accuracy of in-situ gamma radiation measurements for byproducts from industrial facilities. To accomplish the objective, a drive mechanism for rotational measurement of an byproduct simulator and a sample was constructed. Using ISOCS, an efficiency calibration model of the designed object was generated. Then, the sensitivity analysis of the efficiency calibration model was performed, and the efficiency curve of the efficiency calibration model was optimized using the sensitivity analysis results. Finally, the radiation concentration of the simulated subject was estimated, compared, and evaluated with the designed certification value. For the sensitivity assessment of the influencing factors of the efficiency calibration model, the ISOCS Uncertainty Estimator was used for the horizontal and vertical size and density of the measured object. The standard deviation of the measurement efficiency as a function of the longitudinal size and density of the efficiency calibration model decreased with increasing energy region. When using the optimized efficiency calibration model, the measurement efficiency using IUE was improved compared to the measurement efficiency using ISOCS at the energy of ²²⁸Ac (911 keV) for the nuclide under analysis. Using the ISOCS efficiency calibration method, the difference between the measured radiation concentration and the design value for each simulated subject measurement direction was 4.1% (1% to 10%) on average. The difference between the estimated radioactivity concentration and the design value was 3.6% (1~8%) on average when using the ISOCS IUE efficiency calibration method, which was closer to the design value than the efficiency calibration method using ISOCS. In other words, the estimated radioactivity concentration using the optimized efficiency curve was similar to the designed radioactivity concentration. The results of this study can be utilized as the main basis for the development of regulatory technologies for the treatment and disposal of waste generated during the operation, maintenance, and facility replacement of domestic byproduct generation facilities.

• Proceedings of the KSME Conference
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• 2005.11a
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• pp.19.2-19.2
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• 2005